London Olympics (Aug. 4, 2012)

Britain's Mo Farah reacts after winning gold in the men's 10,000-meter final during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/David J. Phillip)

Jimmy Watkins, of the United States, competes during a track cycling men's sprint event, during the 2012 Summer Olympics, Saturday, Aug. 4, 2012, in London. No wonder Watkins is a fast sprinter. He's used to running up slopes with a hose to extinguish fires. The powerfully built Watkins, a 29-year-old firefighter from Bakersfield, Calif., can already be proud of his achievements at the Olympic Velodrome. On Sunday, Aug. 5, 2012, he will compete in the quarterfinals of the sprint tournament, track cycling's blue-ribbon event. (AP Photo/Matt Rourke)

Michael Phelps won the final swim of his Olympic career and finishes the London games with four golds and two silvers.

Runners pass by the Olympic rings in the men's 10,000-meter final during the athletics competition in the Olympic Stadium at the 2012 Summer Olympics, Saturday, Aug. 4, 2012, in London. (AP Photo/David J. Phillip)

Michael Phelps of the United States swims the butterfly leg in the men's 4x100-meter medley relay in London on Saturday. In winning gold in his final event, Phelps retires with twice as many golds as any other Olympian, and his total of 22 medals is easily the best mark.

Britain's Mo Farah (right) crosses the finish line to win gold ahead of Galen Rupp of the United States in the men's 10,000-meter final in London on Saturday. Farah's win was part of a big night for the host nation.

United States' swimmer Michael Phelps holds up a silver trophy after being honored as the most decorated Olympian at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Saturday, Aug. 4, 2012. Phelps was honored with a special individual ceremony after concluding his record-breaking career Saturday as the most decorated Olympian. Phelps pushed the United States in front to win the medley relay Saturday in the final swimming event of the London Games, after which he is retiring. (AP Photo/Matt Slocum)

Britain's Jessica Ennis poses with her gold medal for the heptathlon during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Daniel Ochoa De Olza)

Andy Murray of Great Britain celebrates after defeating Novak Djokovic of Serbia at the All England Lawn Tennis Club in Wimbledon, London at the 2012 Summer Olympics, Friday, Aug. 3, 2012. (AP Photo/Elise Amendola)

United States goalkeeper Amy Swensen tries to save the ball from an attempt by New Zealand during the women's hockey preliminary match at the 2012 Summer Olympics, Saturday, Aug. 4, 2012, in London. (AP Photo/Bullit Marquez)

Jamaica's Shelly-Ann Fraser-Pryce, left, crosses the finish line to win gold ahead of United States' Carmelita Jeter, third from right, Jamaica's Veronica Campbell-Brown, second from right, Trinidad's Kelly-Ann Baptiste, right, and Ivory Coast's Murielle Ahoure, second from left, in the women's 100-meter final during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Matt Dunham)

Members of the United States team Matthew Grevers, left, Michael Phelps, middle and Brendan Hansen celebrates as Nathan Adrian finishes in the men's 4 X 100-meter medley relay at the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics in London, Saturday, Aug. 4, 2012. (AP Photo/Julio Cortez)

Members of the United States women's 4 x 100-meter medley relay team celebrate after winning the gold medal the Aquatics Centre in the Olympic Park during the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Jae C. Hong)

From left to right, Susie Scanlan, Kelley Hurley, Courtney Hurley and Maya Lawrence of the United States celebrate their victory at the end of the women's eppe team bronze medal fencing competition against Russia at the ExCel Centre at the 2012 Summer Olympics on Saturday, Aug. 4, 2012, in London. (AP PhotoDamir Sagolj, Pool)

Britain's Mo Farah, right, embraces Wenlock, the games mascot, after winning gold in the men's 10,000-meter during the athletics in the Olympic Stadium at the 2012 Summer Olympics, London, Saturday, Aug. 4, 2012. (AP Photo/Matt Dunham)

United States' goalkeeper Amy Swensen saves the ball from an attacking Anita Punt of New Zealand during the women's hockey preliminary match at the 2012 Summer Olympics, Saturday, Aug. 4, 2012, in London. (AP Photo/Bullit Marquez)

Stanford Stickney of San Francisco, Calif., reacts during a beach volleyball match against the United States and the Netherlands at the 2012 Summer Olympics, Saturday, Aug. 4, 2012, in London. (AP Photo/Dave Martin)